The fifth season of TNT’s cult series "Leverage" is shaping up to be the best one yet. Since the first episode the series continues to gain momentum with audiences -- an uncommon feat for most television shows. But Leverage isn’t like most television shows.

This cool, fast-paced, thoroughly witty hour of summer television features Nate Ford (Timothy Hutton) and his team of grifters, thieves and hackers using their wicked skills to help those who have been wronged.

But all of this is about to change.

MTVGeek has exclusively learned that Catherine Dent (The Shield, The Mentalist) is set to guest star in the winter finale of Leverage, playing Agent Ellen Casey, an Interpol agent at a high security government building in downtown Portland. She is the lead investigator in the Leverage squad’s finest and most elaborate job yet. Casey is cunning and quick to key in on the squad’s plans, but is she quick enough?

Fans of the series will be happy to know that Mark Sheppard (Supernatural, Doctor Who) will be returning to plague the squad as James Sterling -- their long time nemesis. As Agent Casey’s boss, will his involvement finally spell the end of the Leverage crew?

Tune into LEVERAGE Sundays on TNT for more, and keep your eyes on MTV Geek for more exciting Leverage news.